Posts Tagged lower limb

[ARTICLE] The Control of a Lower Limb Exoskeleton for Gait Rehabilitation: A Hybrid Active Force Control Approach – Full Text

Abstract

This paper focuses on the modelling and control of a three-link lower limb exoskeleton for gait rehabilitation. The exoskeleton that is restricted to the sagittal plane is modelled together with a human lower limb model. In this case study, a harmonic disturbance is excited at the joints of the exoskeleton whilst it is carrying out a joint space trajectory tracking. The disturbance is introduced to examine the compensating efficacy of the proposed controller. A particle swarm optimised active force control strategy is proposed to augment the disturbance regulation of a conventional proportional-derivative (PD) control law. The simulation study suggests that the proposed control approach mitigates well the disturbance effect whilst maintaining its tracking performance which is seemingly in stark contrast with its traditional PD counterpart.

Source: The Control of a Lower Limb Exoskeleton for Gait Rehabilitation: A Hybrid Active Force Control Approach

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[ARTICLE] Short-term effects of physiotherapy combining repetitive facilitation exercises and orthotic treatment in chronic post-stroke patients – Full Text PDF

Abstract.

[Purpose] This study investigated the short-term effects of a combination therapy consisting of repetitive facilitative exercises and orthotic treatment.

[Subjects and Methods] The subjects were chronic post-stroke patients (n=27; 24 males and 3 females; 59.3 ± 12.4 years old; duration after onset: 35.7 ± 28.9 months) with limited mobility and motor function. Each subject received combination therapy consisting of repetitive facilitative exercises for the hemiplegic lower limb and gait training with an ankle-foot orthosis for 4 weeks. The Fugl-Meyer assessment of the lower extremity, the Stroke Impairment Assessment Set as a measure of motor performance, the Timed Up & Go test, and the 10-m walk test as a measure of functional ambulation were evaluated before and after the combination therapy intervention.

[Results] The findings of the Fugl-Meyer assessment, Stroke Impairment Assessment Set, Timed Up & Go test, and 10-m walk test significantly improved after the intervention. Moreover, the results of the 10-m walk test at a fast speed reached the minimal detectible change threshold (0.13 m/s).

[Conclusion] Short-term physiotherapy combining repetitive facilitative exercises and orthotic treatment may be more effective than the conventional neurofacilitation therapy, to improve the lower-limb motor performance and functional ambulation of chronic post-stroke patients.

 

INTRODUCTION

The mobility of many stroke survivorsislimited, and most identify walking as a top priority for rehabilitation1) . One way to manage ambulatory difficulties is with an ankle-foot orthosis (AFO) or a foot-drop splint, which aims to stabilize the foot and ankle while weight-bearing and lift the toes while stepping1) . In stroke rehabilitation, various approaches, including robotic assistance, strength training, and task-related/virtual reality techniques, have been shown to improve motor function2) . The benefits of a high intensity stroke rehabilitation program are well established, and although no clear guidelines exist regarding the best levels of intensity in practice, the need for its incorporation into a therapy program is widely acknowledged2) . Repetitive facilitative exercises (RFE), which combine a high repetition rate and neurofacilitation, are a recently developed approach to rehabilitation of stroke-related limb impairment2–5) . In the RFE program, therapists use muscle spindle stretching and skin-generated reflexes to assist the patient’s efforts to move an affected joint5) . Previous studies have shown that an RFE program improved lower-limb motor performance (Brunnstrom Recovery Stage, foot tapping, and lower-limb strength) and the 10-m walk test in patients with brain damage3) . An AFO is an assistive device to help stroke patients with hemiplegia walk and stand. A properly prescribed AFO can improve gait performance and control abnormal kinematics arising from coordination deficits6) . Gait training with an AFO has been also reported to improve gait speed and balance in post-stroke patients7, 8) . Therefore, we hypothesized that short-term physiotherapy combining RFE and orthotic treatment would improve both lower-extremity motor performance and functional ambulation. The present study aimed to confirm the efficacy of a combination therapy consisting of RFE for the hemiplegic lower limb and gait training with AFO.

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[Abstract] Changes in lower limb muscle activity after walking on a split-belt treadmill in individuals post-stroke

Abstract

Background: There is growing evidence that stroke survivors can adapt and improve step length symmetry in the context of split-belt treadmill (SBT) walking. However, less knowledge exists about the strategies involved for such adaptations. This study analyzed lower limb muscle activity in individuals post-stroke related to SBT-induced changes in step length.

Methods: Step length and surface EMG activity of six lower limb muscles were evaluated in individuals post-stroke (n=16) during (adaptation) and after (after-effects) walking at unequal belt speeds.

Results: During adaptation, significant increases in EMG activity were mainly found in proximal muscles (p⩽0.023), whereas after-effects were observed particularly in the distal muscles. The plantarflexor EMG increased after walking on the slow belt (p⩽0.023) and the dorsiflexors predominantly after walking on the fast belt (p⩽0.017) for both, nonparetic and paretic-fast conditions. Correlation analysis revealed that after-effects in step length were mainly associated with changes in distal paretic muscle activity (0.522⩽ r ⩽0.663) but not with functional deficits. Based on our results, SBT walking could be relevant for training individuals post-stroke who present shorter paretic step length combined with dorsiflexor weakness, or individuals with shorter nonparetic step length and plantarflexor weakness.

Source: Changes in lower limb muscle activity after walking on a split-belt treadmill in individuals post-stroke

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[ARTICLE] Biofeedback improves performance in lower limb activities more than usual therapy in people following stroke: a systematic review – Full Text

Abstract

Question: Is biofeedback during the practice of lower limb activities after stroke more effective than usual therapy in improving those activities, and are any benefits maintained beyond the intervention?

Design: Systematic review with meta-analysis of randomised trials with a PEDro score > 4.

Participants: People who have had a stroke.

Intervention: Biofeedback (any type delivered by any signal or sense) delivered concurrently during practice of sitting, standing up, standing or walking compared with the same amount of practice without biofeedback.

Outcome measures: Measures of activity congruent with the activity trained.

Results: Eighteen trials including 429 participants met the inclusion criteria. The quality of the included trials was moderately high, with a mean PEDro score of 6.2 out of 10. The pooled effect size was calculated as a standardised mean difference (SMD) because different outcome measures were used. Biofeedback improved performance of activities more than usual therapy (SMD 0.50, 95% CI 0.30 to 0.70).

Conclusion: Biofeedback is more effective than usual therapy in improving performance of activities. Further research is required to determine the long-term effect on learning. Given that many biofeedback machines are relatively inexpensive, biofeedback could be utilised widely in clinical practice.

[Stanton R, Ada L, Dean CM, Preston E (2016) Biofeedback improves performance in lower limb activities more than usual therapy in people following stroke: a systematic review. Journal of Physiotherapy 63: 11–16]

Introduction

This is an update of a systematic review1 that examined the effect of biofeedback in training lower limb activities after stroke. Biofeedback is equipment that transforms biological signals into an output that can be understood by the learner, providing information to the learner that is not consciously available. That is, biofeedback takes intrinsic physiological signals and makes them extrinsic, giving the person immediate and accurate feedback of information about these body functions. Biofeedback can be delivered through various senses, such as visual, auditory and tactile systems, and can provide information about the kinematics, kinetics and/or electromyography of activities. Biofeedback is available from medical equipment (eg, electromyography, force platforms and positional devices traditionally used in clinical practice); or from non-medical equipment that is increasingly available and used in stroke rehabilitation (eg, recreational games such as the Nintendo® Wii™). Biofeedback can be used in addition to verbal content; however, it also has the advantage that it can be set up for the patient to use when left to practise alone. However, biofeedback is not commonly used in stroke rehabilitation.2

The previous version of this review,2 which was published in 2011, examined biofeedback broadly in training lower limb activities after stroke, including trials where any form of biofeedback was provided during practice of the whole activity (rather than part of the activity), with outcomes measured during the same activity. Twenty-two trials met the inclusion criteria and were included in the review; however, meta-analyses demonstrated significant heterogeneity that was best explained by the quality of the included trials. When analyses were limited to higher quality trials (PEDro score > 4), biofeedback had a moderate effect in the short term (10 trials, 241 participants, SMD 0.49, 95% CI 0.22 to 0.75) compared with usual therapy, which was maintained beyond intervention (five trials, 138 participants, SMD 0.41, 95% CI 0.06 to 0.75), suggesting that learning had occurred. For a direct comparison of the effect of biofeedback interventions and usual therapy (which includes therapist communication), a post hoc meta-analysis was conducted of those trials where the amount of practice was equal in each group. That is, trials where the control group practised the same activity for the same amount of time as the experimental group, with the only difference being the substitution of biofeedback for therapist communication (presumably including feedback) in the experimental group. This meta-analysis demonstrated a moderate effect of a similar magnitude to the overall analysis (eight trials, 170 participants, SMD 0.51, 95% CI 0.20 to 0.83), suggesting that biofeedback is superior to therapist communication.

Since that review1 was published in 2011, a number of additional trials have been published that investigated the effect of biofeedback, warranting an update of the review. In particular, the potential of using recreational games in stroke rehabilitation has gained attention. The inclusion criteria for this updated review incorporated findings from the previous review. Specifically, this meant that the updated review would include any randomised trial investigating biofeedback from any signal (position, force, EMG) via any sense (visual, auditory, tactile), delivered concurrently during whole activity practice, compared with usual therapy that was practice of the same activity for the same amount of time in the control group with no biofeedback (but presumably with therapist communication), with outcome measures at the activity level and congruent with the activity trained. This ensures a true comparison of the effect of biofeedback compared with usual therapist communication. For the biofeedback intervention, inclusion in this update was based on whether the biofeedback delivered was concurrent rather than terminal feedback. This meant that commercially available recreational games would be included if the majority of the games played within the study delivered concurrent biofeedback, rather than inclusion based on the equipment itself. In order to make recommendations based on the highest level of evidence, this review included only randomised trials with a PEDro score > 4.

Therefore, the research questions for this systematic review were:

  • 1. In adults following stroke, is biofeedback during the practice of lower limb activities more effective than usual therapy in improving those activities in the short term?
  • 2. Are any benefits maintained beyond the intervention?

Continue —> Biofeedback improves performance in lower limb activities more than usual therapy in people following stroke: a systematic review – Journal of Physiotherapy

 

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[Systematic Review] Biofeedback improves performance in lower limb activities more than usual therapy in people following stroke – Full Text

Abstract

Question: Is biofeedback during the practice of lower limb activities after stroke more effective than usual therapy in improving those activities, and are any benefits maintained beyond the intervention? Design: Systematic review with meta-analysis of randomised trials with a PEDro score > 4. Participants: People who have had a stroke. Intervention: Biofeedback (any type delivered by any signal or sense) delivered concurrently during practice of sitting, standing up, standing or walking compared with the same amount of practice without biofeedback. Outcome measures: Measures of activity congruent with the activity trained. Results: Eighteen trials including 429 participants met the inclusion criteria. The quality of the included trials was moderately high, with a mean PEDro score of 6.2 out of 10. The pooled effect size was calculated as a standardised mean difference (SMD) because different outcome measures were used. Biofeedback improved performance of activities more than usual therapy (SMD 0.50, 95% CI 0.30 to 0.70). Conclusion: Biofeedback is more effective than usual therapy in improving performance of activities. Further research is required to determine the long-term effect on learning. Given that many biofeedback machines are relatively inexpensive, biofeedback could be utilised widely in clinical practice. [Stanton R, Ada L, Dean CM, Preston E (2016) Biofeedback improves performance in lower limb activities more than usual therapy in people following stroke: a systematic review.Journal of PhysiotherapyXX: XX-XX]

Introduction

This is an update of a systematic review1 that examined the effect of biofeedback in training lower limb activities after stroke. Biofeedback is equipment that transforms biological signals into an output that can be understood by the learner, providing information to the learner that is not consciously available. That is, biofeedback takes intrinsic physiological signals and makes them extrinsic, giving the person immediate and accurate feedback of information about these body functions. Biofeedback can be delivered through various senses, such as visual, auditory and tactile systems, and can provide information about the kinematics, kinetics and/or electromyography of activities. Biofeedback is available from medical equipment (eg, electromyography, force platforms and positional devices traditionally used in clinical practice); or from non-medical equipment that is increasingly available and used in stroke rehabilitation (eg, recreational games such as the Nintendo® Wii™). Biofeedback can be used in addition to verbal content; however, it also has the advantage that it can be set up for the patient to use when left to practise alone. However, biofeedback is not commonly used in stroke rehabilitation.2

Continue —> Biofeedback improves performance in lower limb activities more than usual therapy in people following stroke: a systematic review

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[WEB SITE] Lower-Limb Robot Exoskeleton Aims to Assist in Gait Rehab – Rehab Managment

Published on October 28, 2016

Researchers from China and Denmark have developed a wearable lower-limb robot exoskeleton designed to help aid the gait rehabilitation of stroke and spinal cord injury patients.

The research team, from Beihang University in China and Aalborg University in Denmark, report in Review of Scientific Instruments that the robot exoskeleton is intended to help stroke patients strengthen their physical fitness, aid the rehabilitation training of paralyzed patients, or to assist those who need help performing daily activities.

In their exoskeleton design, the team focused on the knee joint.

“Our new design features a parallel knee joint to improve the bio-imitability and adaptability of the exoskeleton,” explains Weihai Chen, a professor at Beihang University’s School of Automation Science and Electrical Engineering, in Beijing, China, in a media release from American Institute of Physics.

Specifically, the release explains, the exoskeleton taps a hybrid serial-parallel kinematic structure consisting of a 1-degree of freedom (DOF) hip joint module and a 2-DOF knee joint module in the sagittal plane. And a planar 2-DOF parallel mechanism helps to fully accommodate the motion of the human knee—enabling rotation and relative sliding.

Chen notes that the exoskeleton’s design may be the first known use of a parallel mechanism at the knee joint to imitate skeletal muscles.

“Our design goes beyond solving the transparency problem in the knee joint — and it’s a simple structure,” Chen adds. “Unlike most previous exoskeletons, which simplified the knee joint as a pin joint, ours provides 2 DOF to make the exoskeleton’s movement consistent with a patient’s natural movement.”

Chen and others on the team are exploring the use of electromyography signals to control the exoskeleton.

“We can obtain the movement intention from a patient’s electroencephalogram (EEG)—brain signals—and use it to directly control the exoskeleton,” Chen explains. “These improvements should enable easy control and make the exoskeleton act as part of the human body.”

The team’s next step will be to collaborate with hospitals to test the exoskeleton with patients.

“We’d also like to commercialize it in the near future, so we’ll be working to make the robot’s appearance fancier and enhancing the user interface to be more user friendly,” Chen notes in the release.

[Source(s): American Institute of Physics, Newswise]

[Photo of exoskeleton prototype courtesy of Beihang University]

Source: Lower-Limb Robot Exoskeleton Aims to Assist in Gait Rehab – Rehab Managment

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[Abstract] Repetitive task training for improving functional ability after stroke – The Cochrane Library

First published: 14 November 2016

Abstract

Background

Repetitive task training (RTT) involves the active practice of task-specific motor activities and is a component of current therapy approaches in stroke rehabilitation.

Objectives

Primary objective: To determine if RTT improves upper limb function/reach and lower limb function/balance in adults after stroke.

Secondary objectives: 1) To determine the effect of RTT on secondary outcome measures including activities of daily living, global motor function, quality of life/health status and adverse events. 2) To determine the factors that could influence primary and secondary outcome measures, including the effect of ‘dose’ of task practice; type of task (whole therapy, mixed or single task); timing of the intervention and type of intervention.

Search methods

We searched the Cochrane Stroke Group Trials Register (4 March 2016); the Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library 2016, Issue 5: 1 October 2006 to 24 June 2016); MEDLINE (1 October 2006 to 8 March 2016); Embase (1 October 2006 to 8 March 2016); CINAHL (2006 to 23 June 2016); AMED (2006 to 21 June 2016) and SPORTSDiscus (2006 to 21 June 2016).

Selection criteria

Randomised/quasi-randomised trials in adults after stroke, where the intervention was an active motor sequence performed repetitively within a single training session, aimed towards a clear functional goal.

Data collection and analysis

Two review authors independently screened abstracts, extracted data and appraised trials. We determined the quality of evidence within each study and outcome group using the Cochrane ‘Risk of bias’ tool and GRADE (Grades of Recommendation, Assessment, Development and Evaluation) criteria. We did not assess follow-up outcome data using GRADE. We contacted trial authors for additional information.

Main results

We included 33 trials with 36 intervention-control pairs and 1853 participants. The risk of bias present in many studies was unclear due to poor reporting; the evidence has therefore been rated ‘moderate’ or ‘low’ when using the GRADE system.

There is low-quality evidence that RTT improves arm function (standardised mean difference (SMD) 0.25, 95% confidence interval (CI) 0.01 to 0.49; 11 studies, number of participants analysed = 749), hand function (SMD 0.25, 95% CI 0.00 to 0.51; eight studies, number of participants analysed = 619), and lower limb functional measures (SMD 0.29, 95% CI 0.10 to 0.48; five trials, number of participants analysed = 419).

There is moderate-quality evidence that RTT improves walking distance (mean difference (MD) 34.80, 95% CI 18.19 to 51.41; nine studies, number of participants analysed = 610) and functional ambulation (SMD 0.35, 95% CI 0.04 to 0.66; eight studies, number of participants analysed = 525). We found significant differences between groups for both upper-limb (SMD 0.92, 95% CI 0.58 to 1.26; three studies, number of participants analysed = 153) and lower-limb (SMD 0.34, 95% CI 0.16 to 0.52; eight studies, number of participants analysed = 471) outcomes up to six months post treatment but not after six months. Effects were not modified by intervention type, dosage of task practice or time since stroke for upper or lower limb. There was insufficient evidence to be certain about the risk of adverse events.

Authors’ conclusions

There is low- to moderate-quality evidence that RTT improves upper and lower limb function; improvements were sustained up to six months post treatment. Further research should focus on the type and amount of training, including ways of measuring the number of repetitions actually performed by participants. The definition of RTT will need revisiting prior to further updates of this review in order to ensure it remains clinically meaningful and distinguishable from other interventions.

Plain language summary

Repetitive task training for improving functional ability after stroke

Review question: What are the effects of repeated practice of functional tasks on recovery after stroke when compared with usual care or placebo treatments?

Background: Stroke can cause problems with movement, often down one side of the body. While some recovery is common over time, about one third of people have continuing problems. Repeated practice of functional tasks (e.g. lifting a cup) is a treatment approach used to help with recovery of movement after stroke. This approach is based on the simple idea that in order to improve our ability to perform tasks we need to practice doing that particular task numerous times, like when we first learned to write. The types of practice that people do, and the time that they spend practicing, may affect how well this treatment works. To explore this further we also looked at different aspects of repetitive practice that may influence how well it works.

Study characteristics: We identified 33 studies with 1853 participants. Studies included a wide range of tasks to practice, including lifting a ball, walking, standing up from sitting and circuit training with a different task at each station. The evidence is current to June 2016.

Key results: In comparison with usual care (standard physiotherapy) or placebo groups, people who practiced functional tasks showed small improvements in arm function, hand function, walking distance and measures of walking ability. Improvements in arm and leg function were maintained up to six months later. There was not enough evidence to be certain about the risk of adverse events, for example falls. Further research is needed to determine the best type of task practice, and whether more sustained practice could show better results.

Quality of the evidence: We classified the quality of the evidence as low for arm function, hand function and lower limb functional measures, and as moderate for walking distance and functional ambulation. The quality of the evidence for each outcome was limited due poor reporting of study details (particularly in earlier studies), inconsistent results across studies and small numbers of study participants in some comparisons.

Source: Repetitive task training for improving functional ability after stroke – French – 2016 – The Cochrane Library – Wiley Online Library

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[VIDEO] Lower Limb Neurological Examination – OSCE guide (New Version) – YouTube

Δημοσιεύτηκε στις 16 Φεβ 2015
See the written guide alongside the video on our website http://geekymedics.com/2010/10/02/low…

This video aims to give you an idea of what’s required in the Lower Limb Neurological Examination OSCE.

Always adhere to your medical schools / local hospital trusts guidelines when performing examinations or clinical procedures. Do NOT perform any examination or procedure on patients based purely upon the content of these videos. Geeky Medics accepts no liability for loss of any kind incurred as a result of reliance upon information provided in this video.

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[WEB SITE] Bio-inspired lower-limb ‘wearing robotic exoskeleton’ for human gait rehab

WASHINGTON, D.C., Oct. 25, 2016 — Stroke and spinal cord injury patients often require gait rehabilitation to regain the ability to walk or to help strengthen their muscles. Wearable “robot-assisted training” is quickly emerging as a method that helps improve this rehab process.

In a major advance, researchers from Beihang University in China and Aalborg University in Denmark have designed a lower-limb robot exoskeleton — a wearable robot — that features natural knee movement to greatly improve patients’ comfort and willingness to wear it for gait rehab.

As the team reports this week in Review of Scientific Instruments, from AIP Publishing, their robotic exoskeleton is intended to help stroke patients strengthen their physical fitness, aid the rehabilitation training of paralyzed patients, or to assist those who need help performing daily activities.

Exoskeleton robots aren’t new — they’ve been studied extensively and many designs have focused on lower limbs. This team’s approach focused instead on the knee joint, one of the most complex mechanical systems within the human body and a critical player during gait.

The knee joint’s motion is actuated by several skeletal muscles along its articular surfaces, and its center of rotation moves. The researchers wondered if a parallel mechanism similar to skeletal muscles would be useful for designing a bionic knee joint.

“Our new design features a parallel knee joint to improve the bio-imitability and adaptability of the exoskeleton,” explained Weihai Chen, a professor at Beihang University’s School of Automation Science and Electrical Engineering, in Beijing, China.

Specifically, the team’s exoskeleton taps a hybrid serial-parallel kinematic structure consisting of a 1-degree of freedom (DOF) hip joint module and a 2-DOF knee joint module in the sagittal plane. And a planar 2-DOF parallel mechanism helps to fully accommodate the motion of the human knee — enabling rotation and relative sliding.

Credit: Beihang University

 

For more visit —> Bio-inspired lower-limb ‘wearing robotic exoskeleton’ for human gait rehab – Scienmag

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